Cellular communications systems typically provide interconnect and/or dispatch voice communication services. Interconnect voice communication services are those typically provided by most cellular carriers as circuit-switched communications. Dispatch communication services are commonly known as a walkie-talkie type of call such as Nextel's service identified by the trade name Direct Connect.
One distinguishing characteristic of dispatch communications compared to interconnect communications is immediacy. Specifically, dispatch calls can be setup between a source and destination much quicker than interconnect calls. To that end, FIG. 1A illustrates an exemplary dispatch call setup method 100. In particular, the setup method 100 of FIG. 1A begins with mobile station A attempting to establish communication with mobile station B via dispatch network 105. Initially, mobile station A send a request 110 to the dispatch network 105, which is then forwarded by the dispatch network 105 to mobile station B as request 115. If mobile station B is powered on, it will send a response 120 to the dispatch network, which is in turn forwarded on to mobile station A as response 125. When mobile station A receives the response 125, it will provide an acknowledgement tone to the user indicating that the intended recipient has been reached and that the user may begin speaking. Accordingly, mobile station A will then forward the user's verbal communication (i.e., talk 130) to the dispatch network 105, which will in turn forward the communication (i.e., talk 135) to mobile station B. If, however, mobile station B is not available, the user of mobile station A will be provided with a negative acknowledgement tone. The user of mobile station A will then have to retry the call to mobile station B at a later time. Moreover, this is often a frustrating exercise since the negative acknowledgement tone may not come until some time after the initial communication request 110 was made.
FIG. 1B illustrates another exemplary dispatch call setup method 140. In this method, mobile station A provides an acknowledgement tone to its user before receiving a response from mobile station B. That is, once the initial request 145 is forwarded to mobile station B by the dispatch network as request 150, the user of mobile station A may begin speaking. Mobile station A will forward the user's verbal communication (i.e., talk 155) to the dispatch network 105 before an acknowledgement from mobile station B has been received. If mobile station B is available, it will provide response 160, which will in turn be forwarded to mobile station A as response 165. In this case, dispatch network will also forward the communication (i.e., talk 155) to mobile station B as talk 170. If, on the other hand, mobile station B is not actually available, the user of mobile station A will receive a negative acknowledgement (i.e., response 165) after the user has already begun speaking. As with the method previously described above with reference to FIG. 1A, this can be a frustrating experience for the user since they may be cut off mid-sentence by the negative acknowledgement, and since they had already expected their communication would be delivered.
Therefore, it would be desirable to provide an improved system and method for providing delivery options when a dispatch destination is not available.